1. Field of the Invention
The invention generally relates to a communication device, and more particularly, relates to a communication device comprising antennas with high isolation characteristics.
2. Description of the Related Art
As people demand more and more signal transmissions and higher transmission rates thereof, communication standards are supporting higher and higher data transmission rates. An antenna system with multiple antennas is required to be capable of receiving and transmitting signals at the same time. For example, the communication standard of IEEE 802.11n can support a MIMO (Multi-Input Multi-Output) operation to increase transmission rates. As a matter of fact, it is a future trend to use multiple antennas in a single mobile device. Since multiple antennas are disposed in a limited space of a mobile device, these antennas are very close to each other and result in serious interference therebetween. Thus, high isolation between the antennas is a critical challenge for a designer.
Accordingly, there is a need to design a new communication device, which not only has high isolation between antennas therein but also maintains radiation efficiency thereof, or even enhances radiation efficiency.